Conventionally, a method of using a password specified by a user as an authentication key is generally adopted to ensure security of a program stored in hardware of a factory automation (FA) product. The user having an access authority transmits the password together with a program read request to an FA device. In this case, any user not having the access authority can read the program if the user acquires the password by some means. This implies, for example, that a person with malicious intent may intercept the password and improperly execute reading of the program. Patent Literature 1 proposes a technique that enables to use a hardware key as an authentication key to enhance robustness of user authentication, for example.